Wire feed mechanism



Aug. 9, i949. R. G. HOFFERT WIRE' FEEDMEHANISM Filed Aug. 7, ,1944

, 4TNVEBPFOR R05 GQHOFFEHT Bq W MTT-Y' Patented Aug. 9, 1949 WIRE FEED MECHANISM Roy G. Hoifert, Racine, Wis., assigner to Acme Steel Company, Chicago, Ill., a, corporation of Illinois Application August 7, 1944, serial No. 548,457

2 Claims.

This invention relates generally to wire feeding mechanisms and in particular to a wire feeding mechanism for wire stitching machines.

Feeding mechanisms for Wire stitching machines now in common use generally include a device for feeding the wire to a reciprocating wire cutter, a guide for directing the wire from the feeding device to the cutter and a wire check acting on the wire between the feeding device and a wire carrying spool to check a return movement of the Wire while permitting a feeding movement of the wire. The wire cutter is ordinarily operatively associated with staple forming and staple driving mechanisms.

The wire guide usually comprises a tube member or the like arranged between the feeding device and the cutter, with the wire from the feeding device being pushed through the tube and into the cutter. By virtue of this pushing action the wire, during a wire feeding operation, tends to buckle between the feeding device and the entrance end of the tube. On completion of the feeding operation the wire, as a result of the buckle. acts to straighten itself out whereby the wire, after being cut, creeps outwardly from the outlet end of the tube into the path of the reciprocating cutter while the cutter is on its down stroke. On the cutter upstroke that portion of the Wire in the path. of the cutter is bent or otherwise deformed so as to prevent the passage of the wire into the staple forming mechanism 'whereby the Wire becomes buckled and jammed at the feeding device which is thereby rendered ineifective for feeding purposes. rl'his clogging condition results in a frequent stopping of the wire stitching machine and a considerable loss in time for the purpose of removing the clogged wire.

It is an object of this invention, therefore, to provide improved wire feeding mechanism.

Another object of this invention is to provide a mechanism for feeding wire to a wire cutter in which the wire is prevented from creeping or travelling into the path of the cutter on compietion of a wire feeding operation.

A further object of this invention is to provide a wire check for a wire feeding mechanism which is capable of being removed from and assembled with the mechanism as a complete unit.

A feature of this invention is found in the revision of a mechanism for feeding a wire into a cutter in which a friction or brake unit is adapted to frictionally engage the wire at a posii adjacent to the wir@ cutter to hold the wire nst movement into the cutter on completion of wire feeding operation.

Further obiects, features and advantages of i i ition will become apparent from the follci i. description when taken in connection with the accompanying drawings in which:

Fig. 1 is a front elevational view of the wire feeding mechanism of this invention shown in assembly relation with a wire cutter and a staple forming and. driving device with certain parts being broken away for the purpose of clarity;

Fig. 2 is a sectional view as seen along the line 2 2 in Fig. 1;

Fig. 3 is an enlarged longitudinal sectional view of a wire check taken along the line 3 3 in Fig. 1;

Fig. 4. is a transverse sectional View of the wire check as seen on the line 4-4 in Fig. 3; and

Fig. 5 is an enlarged longitudinal sectional view of a wire brake unit shown generally in Fig. 1.

With reference to the drawings the wire feed mechanism of this invention is shown in Fig. l in assembly relation in a wire stitching machine with a wire cutting and staple forming mechanism. The feed mechanism comprises a pair of feed rollers It each of which is mounted on a shaft Il rotatably carried on a supporting frame or plate member I2. The rollers Il] are rotated in synchronism and in opposite directions by suitable gears (not shown) mounted upon the rear end of the shafts II and operatively associated with a driving motor (not shown) for the stitching machine to provide for one complete revolution of the rollers I0 for each cycle of operation of the stitching machine.

Each roller I0 has a peripheral cam I3, with a feeding of the wire I4 between the rollers taking place when portions of the cams I3 are opposite each other. For a detailed description of the construction and operation of the rollers Ii reference is made to U. S. Patent 2,199,241. The wire I4 from the feed rollers Ill enters a wire guide I5 having a passage I6 therein for slidably receiving the wire and adapted to direct the wire from the feed rollers to a wire cutting device indicated generally as I'I.

As shown in Figs. 1 and 2 the plate member I2 is formed with a pair of upright spaced projections I8 and I9 constituting a guide way for a reciprocally movable sliding block 2I having a pair of staple formers 22 and 23 carried thereon in a spaced relation. Retention of the block ZI between the projections I8 and I9 is accomplished by the provision of a cover block 2E) extended across and secured to the projections by screws 25. The sliding block 2l is reciprocated by means including a cam member 24 mounted on a shaft 26 rotatably supported in the frame member I2, and in driven association with the motor for the stitching machine. A cam groove 2l in the cam 24 is adapted to receive a roller 28 carried on the sliding block 2| adjacent its upper end.

Slidably supported between the staple formers 22 and 23 for reciprocal movement is a staple driver 29 pivoted adjacent .its upper end to one end of a connecting rod 3|, the `opposite end of which is rotatably supported on a shaft member 32 carried on the cam member 24 in an offset relation with the cam shaft 26. The feed rollers III, staple formers 22 and `23 and staple driver 29 are operated in a timed relation, with the staple formers and the driver being reciprocated through a complete cycle for each complete rotation of the feed rollers I.

An anvil 33 located between the plate projections I8 and I9 and below the driver 29 is slidably supported in a transverse opening 34 in the plate member I2. A spring 36 is arranged in compression within a recess in the back of the anvil 33 and a cover 31 for the rear end of the opening 34 to yieldably urge the anvil in a direction outwardly from the front side of the plate member I2. The movement of the anvil by the action of the spring 36 is limited by a stop pin 38 mounted in the plate member I2 and having one end slidable in a lo-ngitudinal groove 39 formed in the anvil 33.

The wire I4 from the guide I5 passes through a cutter tube 4I carried in the plate projection I8 and having its end 42 extended within the path of movement of the staple former 22, which is formed with a longitudinal groove 43 for slidably receiving the extended end 42 of the cutter tube. A cutting tool 44 is mounted at the lower end of the staple former 22 for reciprocal movement therewith in a path adjacent to the cutter tube end 42, with the wire being sheared or cut by the tool 44 as the tool passes across the wire opening in the cutter tube.

In the operation of the stitching machine the wire I4 is fed by the feed rollers III through the guide I and the cutter tube 4I into a transverse slot 46 formed at the forward end of the anvil 33, while the staple formers 22 and 23 and the staple driver 29 are in their up-stroke position, as shown in Figs. 1 and 2.

On completion of the feeding operation the staple formers and the staple driver are moved downwardly whereby the wire I4 is cut by the tool 44 at the end 42 of the cutter tube 4l. The cut wire is then bent over the anvil 33 by the staple formers 22 and 23 and retained between the staple formers as the anvil is moved rearwardly, against the action of the spring 36, by engagement with the downwardly moving driver 29. The staple formers and the staple driver then move downwardly together to a staple driving position, at which time the downward movement of the formers 2.2 and 23 is suspended and the downward movement of the driver 29 is continued to drive the formed staple into a carton or the like.

A member 41 is pivoted at 43 to the staple formers 22 and 23 for pivotal movement therebetween and is yieldably movable to a position between the formers by a spring-pressed member 49 movably carried in the cover block 20. The pivoted member 41 constitutes a support for holding the staple legs against bending inwardly toward each other during the staple driving operation, and is pivoted outwardly from between the staple formers against the action of the spring-pressed member 49 by the driver 25 as it approaches its lowermost or downstroke position.

In operation of the feed rollers I6 the wire I4 is drawn or pulled into the rollers and is then pushed from the feed rollers through the guide I5 and to the cutting mechanism I1. By virtue of this pushing action on the wire I4 by the rollers I@ the wire tends to buckle over that portion thereof indicated as I4a and located between the feed rollers and the entrance end 5I of the guide I5.

On completion of a feeding operation the wire acts to straighten itself out. The return movement of the wire I4 upwardly from the rolls I0 is prevented by a wire check 52, which will be later described. As a result the straightening of the wire portion I4a sometimes results in the wire creeping or moving through the guide I5 and to the cutter mechanism I1. This straightening #lof the wire arises by virtue of the compression pressure produced in the buckled wire portion I4a, with the straightening of the wire being accelerated by any operating vibrations in the stitching machine.

Any creeping of the wire I4 into the cutter mechanism I1 takes effect after the cutter 44 has passed out of a contacting position with the end 42 of the cutter tube 4I. When this wire creeping occurs the end of the wire at the cutter tube end 42 is projected into the path of movement of the cutter 44 while the cutter 44 is in a downstroke position. On the upstroke of the cutter the projected wire end is bent inwardly. In a next feeding operation of the rollers II] the bent end of the Wire is incapable of passing through the transverse slot 46 in the anvil 33, whereby further movement of the wire through the guide I5 is stopped and the wire becomes clogged and jammed between the feed rollers I5 and the entrance end 5I of the tube I5. This jamming, of course, disrupts the operation of the stitching machine and results in a loss of time required for moving the buckled wire, as well as the wire portions at the anvil 33.

In order to eliminate this jamming condition a friction unit 53 is provided on the guide I5 at a position adjacent the cutter mechanism I1 (Figs. 1 and 5). The friction unit includes a sleeve member 54 threadably supported at 56 in the guide I5 and extended to the wire passage I6.

f. Slidably supported within the sleeve 54 is a bearing member 56a. having an end 55 projected into the wire passage I6. The member 56a is forced into frictional engagement with the wire I4 by a spring 51 arranged in compression between the member 56a and a plug 58 threadable in the sleeve 54. As clearly appears in Fig. 5 one side of the wire I4 is frictionally engaged by the bearing member 56a while its opposite side is forced into frictional engagement with a side wall of the passage I6.

The friction unit 53 provides a braking action on the wire I4 whereby any tendency of the buckled wire portion I4a to straighten out is limited to the section of the wire I4 located between the wire check 52 and the friction unit 53. On completion of a feeding operation, therefore, any creeping of the wire outwardly from the guide I5 and in turn from the cutter tube 4I is eliminated. The frictional engagement of the pressure or friction unit 53 with the wire in no way interferes with a normal feeding of the wire into the cutter.

The wire check 52, previously mentioned, provides for a feeding movement of the wire I4 in one direction into the feed rollers II), and prevents a return movement of the wire I4 in an opposite direction. This wire check includes a tubular wire-conducting member 59 (Figs. 3 and 4) having a transversely extended opening 6I adjacent its upper end. Oppositely arranged within the opening 6I are a pair of wire-engaging discs 62 which are retained within the opening 6I by a cap or head member 63 having a tapered inside wall 64, and a collar member 66 slidable on the member 59 and having one end engageable with the discs 62 at positions substantially diametrically opposite from the wire-engaging portions of the discs.

The collar or sleeve member 66 is forced against the discs 62 by a spring 61. It is seen, therefore, that when the wire I4 is fed by the feed rollers I0 the frictional engagement of the discs 62 with the wire I4 is reduced by virtue of the Wire acting to pull the discs 62 downwardly of the inside tapered wall 64 of the cap member 63 against the pressure of the spring 61. On completion of a feeding operation the return movement of the wire M away from the feed rollers l0 is prevented by the forcing of the collar 66 against the discs 62 by the spring 61 and the resultant movement of the discs upwardly of the inside tapered wall 64. For a detailed description of the construction and operation of the wire check 52, as thus far described, reference is made to U. S. Patent No. 2,239,964.

The spring 61 is arranged in compression between the collar 66 and a ring or stop member 68 which is held against movement downwardly of the tube member 59 by a spring clip 69 received in an annular recess 1i formed in the periphery of the tube member 59. The wire check is operatively assembled with the feed rollers l0 by the insertion of the tubular member 59 through a. boss or extension 12 projected forwardly from the plate member I2 at a position above and between the rollers I9. A friction screw 13 is threadable in the boss 12 and against the tubular member 59 to hold the wire check 52 in a xed position. The wire check '52 is thus removable from and connected to the boss 12 as a complete unit. On removal of the wire check for cleaning purposes, such as cleaning dirt accumulations from the discs 62 carried to the discs by the wire I4, there is little chance for the wire check being improperly assembled after the cleaning procedure.

In many of the wire checks now in common use, and as exemplified by the wire check in Patent 2,239,964 mentioned above, the spring 61 is arranged in compression between the collar 66 and the boss portion 12. Since the stitching machine may be serviced by unskilled servicemen this arrangement of the spring 61 oftentimes results in the spring being assembled between the cap member 63 and the collar 66 so as to completely nullify the function of the wire check. By constructing the wire check as a complete operative unit the chances of improperly assembling the spring 61 in the wire check are appreciably reduced.

Although the invention has been described with respect to a preferred embodiment thereof it is to be understood that it is not to be so limited since changes and modifications can be made therein which are within the full intended scope of this invention as dened by the appended claims.

I claim:

1. A wire check adapted to be used with a wire feeding mechanism as a preassembled unit comprising, a wire conducting tubular member having a transverse opening therethrough, a pair of discs oppositely arranged in said opening and adapted to receive a wire therebetween, a head member carried on said tubular member having an annular recess in its lower end, with the inner side wall of said recess being straight along .its outer portion and having an inwardly tapered portion at the top thereof, said tapered portion of the inner side wall being engageable with said discs, a sleeve slidably supported on said tubular member having one end slidably receivable within said recess to engage the peripheries of said discs at points substantially diametrically opposite those portions of the discs which engage the wire, a stop member removably carried on said tubular member, a coil spring arranged in compression between said stop member and the other end of said sleeve member to cause said sleeve member to yieldably hold said discs against said tapered portion, and a fixed supporting member in which said tubular member is secured.

2. A wire check adapted to be used with a wire feeding mechanism comprising, a wire conducting tube, a pair of disks mounted in said tube to engage opposite sides of a wire therein, said tube having parts forming guides for said disks, a head member mounted on said tube and having an opening through which said wire passes, said head member having inclined surfaces adapted when engaged by said disks to force said disks toward each other to cause them to grip said wire, a sleeve slidably mounted on said tube and arranged to engage said disks at points substantially opposite their points of contact with said wire, a coil spring mounted in said tube and engaging said sleeve to force said sleeve into engagement with said disks, a stop member mounted on said tube and engaging the end of said spring opposite said spring, and a supporting member in which said tube is mounted.

ROY G. HOFFERT.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 832,633 Snow Oct. 9, 1906 1,014,829 Lepper et al Jan. 16, 1912 1,042,756 Beeman et al Oct. 29, 1912 1,215,312 Pagiarul Feb. 6, 1917 1,357,752 Weber et al Nov. 2, 1920 1,460,526 Wolf et al July 3, 1923 1,718,200 Baumann June 18, 1929 1,898,565 Munschauer Feb. 21, 1933 2,199,241 Hoffert Apr. 30, 1940 2,239,964 Hoiert Apr. 29, 1941 2,342,115 Schultz July 13, 1943 

